There have been many advances in recent years in the field of endoscopy. Many of these advances have come due to the increased versatility of endoscopic staple and clip applying mechanisms. These mechanisms are placed through the cannula of an endoscopic trocar so that tissue may be cut, stapled or ligated. With use of these endoscopic stapling and ligating mechanisms, there have become available means for the proliferation of endoscopic ligating procedures.
With the advent of these devices, however, there have been certain noted inadequacies. Many of these inadequacies have become perceived solely because of the newness of the endoscopic procedures. Thus, there has been a great opportunity for the discovery of new needs and desires of each individual surgeon, and therefore an explosion in the necessity to meet these requirements.
For instance, there has been perceived a need for venting such an endoscopic applier, in order to equalize pressures within the instrument and to provide a path of least resistance for fluid flow within the instrument. The equalization of pressures minimizes the possibility of failure of the instruments.
In addition, there has been a perceived need for adequate clip advancing mechanisms in order to both longitudinally (along the long axis of the instrument) and transversely support both the clip closing mechanism and the clip during such surgeries.
Also, there has been perceived a need for a mechanism to vary the gap of a ligating clip when closed within the mechanism.
There is yet another perceived need for a mechanism which guarantees that the jaws of the instrument are open when a clip is fed into these jaws. This mechanism insures clip presence during ligating procedures.
There is yet another perceived need for a mechanism to lockout the firing mechanism instrument after the last ligating clip in the cartridge of clips has been fired.
Yet another perceived need is for a restricting means to minimize proximal movement of the clip during application into a vessel. This limitation of movement maintains the ligating clip within the proper forming area of the jaws during ligation.
One additional need is to create a resistance to the torque acting on the endoscopic applier shaft. Resistance of such torque minimizes any transverse deflection of the endoscopic applier tip during usage. Such torque resistance promotes clip placement accuracy.
Still another perceived need is to create smaller jaw spacing, which allows the usage in a smaller cannula during endoscopic procedures. One additional problem encountered in the resolution of this problem is that one must minimize the spacing of the jaws, while still compensating for the torques created during jaw closure.
Yet another perceived need is for a system which minimizes the possibility of double feeding of clips into a clip applier jaws. Such a system may be perceived as the use of a series of valves and springs in order to properly place only one clip within the jaws of the instrument at any one time.
One additional need is for a mechanism which seals an endoscopic clip applier, to prevent the gross loss of pneumoperitoneum, during operations. Such sealing is necessary to maintain pneumoperitoneum throughout the procedure.
One further perceived need is for a method wherein the synchronized feeding of clips into the jaws of an applier is coordinated with the opening and closing of these jaws during use.
Another final perceived need is for a mechanism which prevents backup of a clip about to be fired within such an endoscopic clip applier.
Therefore, it is to be realized that while there currently exist certain endoscopic clip appliers, it continues to be still important to improve on these appliers in many various areas where there are perceived deficiencies or inadequacies.